Lubricating and sealing compound



Patented May 1, 1945 7 LUBRICATING AND SEALING OMPOUND Samuel C. Carney, Bartlesville, Okla", assignor to Phillips Petroleum Company, a corporation oi Delaware No Drawing.

' 7 claims.

. ess, the essential properties of such a lubricant and sealing compound are that: (a) it shall be relatively insoluble in the liquid being processed or in the vapor or condensate, if a vapor is in process; (1)) it shall have lubricating properties while in the presence of the materials in process at-the operating conditions of temperature and pressure; it shall be a plastic material of a Application August 20, 1942, Serial No. 455,545

. installations treating such materials, frequently consistency ranging between that of a No. 2 and No. 6 cup grease, as known in the grease trade.

. The solfter consistencies tend to promote lubrication at the expense of sealing effectiveness, while the harder consistencies more effectively seal the film space between the plug of the valve and the body in which the plug is placed and rotated when opening or closing the valve, especially at high temperatures and pressures.

Known. grease compounds containing animal and vegetable fats, or mineral oils compounded with soaps 'to give the requisite plastic consistency have been satisfactory lubricants for such valves when water or steam is the material passing providing the consistency at the operating temperature is sufficient to maintain a sealing him between the metal surfaces of the valve plug and the side wall.

Conventional lubricants of this type are unsuitable where the material in. process is a liquid hy drocarbon, and especially light hydrocarbons such as propane, butane, or pentane, which dissolve out the fatty or oily constituents. Lubricants which overcome this objection and have been found suited for use with hydrocarbons, especially the light ones, are compounded with materials relatively insoluble in the hydrocarbons. Molasses, glycerine, castor oil, and certain soaps,

suchas sodium ricinoleate, are common insredl-a cuts in these compounds. The plasticity of this type of compound is governed, for the most part,

by the water content of the compound and by the addition of solid material, usually graphite.

But the problem presented when aluminum chlorldaand especially the sludge formed when aluminum chloride reacts with hydrocarbons, is

present in the hydrocarbon stream, has passed heretofore unsolved. Thus, plug-type valves, in

fall due to the corrosive nature of the aluminum chloride on both the valve lubricant and the me= taliic valve parts. Causes of valve failure may be briefly summed up as follows:' (a) The materials used in valve lubricant compounds for use with hydrocarbons are for the most part of high molecular weight and react chemically with aluminum chloride; (1)) aluminum chloride, when present by sublimation in vapor streams and by solution in liquid hydrocarbon streams, tends to deposit in crystalline form between the valve plug and the valve walls, and freezes the plug firmly in position so that it cannot be rotated; (c) the presence of aluminum chloride and of hydrogen chloride, the latter being frequently used in conjunction with the aluminum chloride or resulting from reaction with water, necessitates the operation of the system in a strictly anhydrou condition. If water is present in the lubricant and sealing compound, it is quickl removed by the anhydrous materials in process, thus destroying both. the plasticity and lubricating properties of Another object of this invention is to provide a lubricant and sealing compound suitable for use with plug-type valves when treating hydr0carbons,

Still another object of this invention is to provide a lubricant and sealing compound suitable for use with plug-type valves when treating hydrocarbons containing aluminum and/or hydrogen chloride.

Still other objects and advantages will be apparent to those skilled in the art from a careful study of the following description and disclosure.

1 have discovered that a homogeneous mixture of an aluminum soap and a sodium soap, in which the aluminum soap is formed by the conversion of a part of the sodium soap by use of an alumi num salt, and plasticized by use of a hydrocarbon liquid, serves well as a plug valve lubricant and sealing agent. The plasticizing agent maybea hydrocarbon liquid, preferably a paramnic liquid boiling from about 300 to 400 F., end'the sodium soap is one substantially insoluble in hydrocarbons, and may be preferably such as sodium oleate or palmitate. The-final compound, prepared as fully disclosed hereinafter, contains essentially no water but may or may not contain the inorganic salts formed by the conversion of the sodium to the aluminum soap.

. Though my compound may be prepared by numerous procedures, I have found the following method for its preparation to be most satisfac- To one pound of commercial sodium soap, for

ticles. In a separate container dissolve 0.49-

pound of ammonium alum in a'minimumamount of boiling water and add this solution to the softened sodium soap, while continuing to heat the mixture. This treatment renders the soap insoluble in water and the thick, doughy mixture is well stirred and kneaded with continued heating to insure complete combination of the alum. By using these above mentioned weight proportions of sodium soap, considered a sodium stearate, and ammonium alum, inv the weight proportions given, when fully reacted, will result in substantially complete conversion of the sodium soap to the aluminum soap.

If, at this stage of the preparation, free water remains, it may be drained off and, of course,

though I have not found it necessary, the plastic material may be added much more easily'and with more uniform blending by stirring it into the heated liquid before the latter has cooled sufiicient to become plastic.-

It is of coursepossible to soften all the sodium.

soap with water and to add thereto such a weight of the alum or other aluminum salt, as will convert only the desired percentage to aluminum soap. Though I do'not know the reason, I have found that when the compound is prepared in this manner the mass does not liquefy on heating but remains plastic with consequent greater difficulty in heating to the temperature necessary for its dehydration.

It is possible to prepare apparently the same compound as hereinbefore disclosed by milling mass may be washed with water to remove the inorganic salts of the reaction. I continue to into a mixture of anhydrous commercial aluminum and sodium soaps in the desired proportions, sufficient hydrocarbon to plasticize the mass, I have found that the compound when so prepared tends tobe crumbly and granular and does not adhere to the metal surfaces as well as when prepared in the homogeneous liquid phase by my preferred method.

ammonium alum it will be obvious to chemists that equivalent weights of other aluminum salts heat and knead the plastic aluminum soap so formed to a temperature of about 250 F. and then, with continued heating and stirring begin to add commercial sodium soap. With theaddition of this latter sodium soap, the plastic mass of aluminum soap, together with the added sodium soap, will melt-down to a homogeneous liquid of relatively low viscosity, and I continue to the liquid until from 1 to 3 pounds of sodium soap have been added. Heating is further continued until a temperature of 400 to 500 F. is .reached to dehydrate the mixture and then the mass is cooled to a temperature of 120 to 150 R, whereupon it becomes a plastic mass. If cooled below approximately 120 F. it becomes too hard for easy plasticizing. While still plastic, due toits temperature of 120 to 150 F., I incorporate into the mass by suitable mechanical mixing, a, liquid hydrocarbon, preferably parafiinic in nature and of reasonably low molecular weight, allowing the mass to cool during this plasticizing treatment. The amount of liquid parafiinic hydrocarbon added is governed by the plasticity desired.

In the final compounded material a harder. consistency is attained by higher percentage of sodium soap and a lower percentage of hydrocarbon added. This type of compound gives the maximum sealing effect in the plug-type valve, while softer consistencies are'attained by "reducing the ercentage of sodium soap in the total mass and increasing the percentage of hydrocarbon plasticizing agent. This latter compound gives maximum lubricating effect.

I have found that from 10% to 50% of aluminum soap in acompound prepared as above disclosed is useful for the lubrication and sealing of various plug-type valves at the various temperatures found in hydrocarbon chemical plants.

If the finished compound is protected from air andv subsequent evaporation by storage in closed containers, the plasticizing hydrocarbon may be add the sodium soap with heating and stirring of and suitable in other respects, may be used ,instead.

I have found that the plastic aluminum soap prepared as herein described, but without addition of the dry sodium soap, is useful as a loosening lubricant for the said plug-type valves, when through infrequent opening or closing they have become difllcult to turn. This gives a maximum of lubricating effect though usually anv insufficient sealing effect. When this is used for loos ening a tight plug, it is well to follow with a. lubrication of the fully prepared compound.

The use of my compound is not limited to the types of valves disclosed, but it will be found a useful lubricant and impregnating material for fibrous packing of many types used on pumprods and shafts and other moving parts exposed to the operating conditions herein described.

It will be obvious to those skilled in the art that the materials used and method of preparation described may be altered and yet remain within the intended spirit and scope of my invention.

What I claim is:

1. A method for preparing a valve sealing and lubricating composition essentially resistant to the corrosive, action of aluminum chloride comprising the steps of adding a water solution of aluminum alum to a plastic mass of sodium soap and water, the amount of aluminum alum being essentially sumcient to convert completely the.

sodium soap to the corresponding aluminum soap, heating the mixture during this said conversion step, and continuing heating while adding addi tional sodium soap in amount approximately equal to 1 to 3 times the amount above reacted with the aluminum alum, and further heating the mixture thus obtained until essentially free of water, cooling the water free mixture untilit becomes plastic, adding with stirring a liquid parafiinic hydrocarbon material boiling below approximately 400 1?. in an amount sufficient to obtain a resulting mixture of desired plasticity, and cooling this final mixture.

-2. A method for preparing a .valve sealing and lubricating composition essentially resistant to the corrosive action of aluminum chloride comprising the steps of adding a water solution of aluminum alum'to a plastic mass of sodium oleate and water, the amount of aluminum alumbeing essentially suflicient to convert completely the sodium oleate to the corresponding aluminum oleate, heating the mixture during this said conversion step, and continuing heating while adding additional sodium oleatein amount approximately equal to 1 to 3 times the amount above reacted with the aluminum alum, and further heating the mixture thus obtained until essentially free of water, cooling the water free mixture until it becomes plastic, adding with stirring a liquidparafilnic hydrocarbon material boiling below approximately 400 F, in an amount sufllcient to obtain a resulting mixture of desired plasticity, and cooling this final mixture.

3. A method for preparing a valve sealing and lubricating composition essentially resistant to the corrosive action of aluminum chloride comprising the steps of adding a water solution of aluminum alum to a plastic mass of sodium palmitate and water, the amount of aluminum alum being essentially suflicient to convert completely the sodium palmitate to the corresponding aluminum palmitate, heating the mixture during this said conversion step, and continuing heating while adding additional sodium palmitate in amount approximately equal to 1- to 3 times the amount above reacted with the aluminum alum, and further heating the mixture thus obtained until essentially free of water, cooling the water free mixture until it becomes plastic, adding with stirring a liquid paraifinic hydrocarbon material boiling belowapproximately 400 F. in an amount sufilcient to obtain a resulting mixture of desired 4 plasticity, and cooling this final mixture.

4. A method for preparing a valve sealing and lubricating composition essentially resistant to the corrosive action of aluminum chloride comprising the steps of adding a water soluble aluminum compound to a plastic mass of sodium soap and water, the amount of water soluble aluminum compound being-essentially sufllcient to convert completely the sodium soap to the corresponding aluminum soap, heating the mixture during this said conversion step, and continuing heating while adding additional sodium soap in amount approximately equal to 1 to 3 times the amount above reacted with the aluminum compound, and further heating the mixture thus obtained until essentially free of water, cooling the water free mixture until it becomes plastic, adding with stirring a liquid paraflinic hydrocarbon material boiling below approximately 400 F. in an amount v sufilcient to obtain a resulting mixture of desired one part aluminum oleate, and a suflicient quantity of a non-viscous, non-lubricating liquid paraflinic hydrocarbon material boiling below approximately 400 F., to form a plastic composition.

7. An anhydrous valve lubricating and sealing composition comprising 1 to 3 parts sodium palmitate, one part aluminum palmitate, and a suflicient quantity of a non-viscous, non-lubricating liquid parafllnic hydrocarbon material boiling below approximately 400 to form a plastic composition.

' S AMUEL C. CARNEY. 

